Argentaffin pulmonary tumorlets.

The left lung, surgically removed from a patient, was found to be bronchiectasic and polycystic. Using light microscopy it was possible to locate multiple tumorlets originating from the Kulchitsky cells of the bronchial and bronchiolar mucosae. With the traditional histochemical staining, argyrophilia and argentaffinity were demonstrated. The latter, not previously reported in the literature, suggests the presence of different monoamines in the neurosecretory cytoplasmic granules of the tumorlet cells.